Imashini zifunga, zizwi kandi kwifungisha-gufunga cyangwa gufunga ibyuma, ni ibice byabugenewe byabugenewe bigamije gutanga kashe itekanye kandi idashobora kumeneka mubikorwa bitandukanye byinganda nubukanishi. Iyi miyoboro igaragaramo igishushanyo cyihariye kirimo ikintu gifunga kashe, mubisanzwe O-impeta cyangwa isabune idashobora kwihanganira, ikaba yinjiye muburyo bwa screw. Iyo icyuma gifunga kashe gifunzwe ahantu, ikintu cyo gufunga gikora kashe ifatanye hagati yimigozi nubuso bwo guhuza, bikabuza kunyuramo amazi, imyuka, cyangwa ibyanduye.